987 resultados para phospholipid-composition


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Nepsilon-(Carboxymethyl)lysine (CML) is a stable chemical modification of proteins formed from both carbohydrates and lipids during autoxidation reactions. We hypothesized that carboxymethyl lipids such as (carboxymethyl)phosphatidylethanolamine (carboxymethyl-PE) would also be formed in these reactions, and we therefore developed a gas chromatography-mass spectrometry assay for quantification of carboxymethylethanolamine (CME) following hydrolysis of phospholipids. In vitro, CME was formed during glycation of dioleoyl-PE under air and from linoleoylpalmitoyl-PE, but not from dioleoyl-PE, in the absence of glucose. In vivo, CME was detected in lipid extracts of red blood cell membranes, approximately 0.14 mmol of CME/mol of ethanolamine, from control and diabetic subjects, (n = 22, p > 0.5). Levels of CML in erythrocyte membrane proteins were approximately 0.2 mmol/mol of lysine for both control and diabetic subjects (p > 0.5). For this group of diabetic subjects there was no indication of increased oxidative modification of either lipid or protein components of red cell membranes. CME was also detected in fasting urine at 2-3 nmol/mg of creatinine in control and diabetic subjects (p = 0.085). CME inhibited detection of advanced glycation end product (AGE)-modified protein in a competitive enzyme-linked immunosorbent assay using an anti-AGE antibody previously shown to recognize CML, suggesting that carboxymethyl-PE may be a component of AGE lipids detected in AGE low density lipoprotein. Measurement of levels of CME in blood, tissues, and urine should be useful for assessing oxidative damage to membrane lipids during aging and in disease.

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We analyze ways by which people decompose into groups in distributed systems. We are interested in systems in which an agent can increase its utility by connecting to other agents, but must also pay a cost that increases with the size of the sys- tem. The right balance is achieved by the right size group of agents. We formulate and analyze three intuitive and realistic games and show how simple changes in the protocol can dras- tically improve the price of anarchy of these games. In partic- ular, we identify two important properties for a low price of anarchy: agreement in joining the system, and the possibil- ity of appealing a rejection from a system. We show that the latter property is especially important if there are some pre- existing constraints regarding who may collaborate (or com- municate) with whom.

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In most previous research on distributional semantics, Vector Space Models (VSMs) of words are built either from topical information (e.g., documents in which a word is present), or from syntactic/semantic types of words (e.g., dependency parse links of a word in sentences), but not both. In this paper, we explore the utility of combining these two representations to build VSM for the task of semantic composition of adjective-noun phrases. Through extensive experiments on benchmark datasets, we find that even though a type-based VSM is effective for semantic composition, it is often outperformed by a VSM built using a combination of topic- and type-based statistics. We also introduce a new evaluation task wherein we predict the composed vector representation of a phrase from the brain activity of a human subject reading that phrase. We exploit a large syntactically parsed corpus of 16 billion tokens to build our VSMs, with vectors for both phrases and words, and make them publicly available.

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Provides incipits of the dances not then in modern editions.

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Six amphiphilic star copolymers comprising hydrophilic units of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and hydrophobic units of methyl methacrylate (MMA) were prepared by the sequential group transfer polymerization (GTP) of the two comonomers and ethylene glycol dimethacrylate (EGDMA) cross-linker. Four star-block copolymers of different compositions, one miktoarm star, and one statistical copolymer star were synthesized. The molecular weights (MWs) and MW distributions of all the star copolymers and their linear homopolymer and copolymer precursors were characterized by gel permeation chromatography (GPC), while the compositions of the stars were determined by proton nuclear magnetic resonance (H-1 NMR) spectroscopy. Tetrahydrofuran (THF) solutions of all the star copolymers were characterized by static light scattering to determine the absolute weight-average MW ((M) over bar (w)) and the number of arms of the stars. The R, of the stars ranged between 359,000 and 565,000 g mol(-1), while their number of arms ranged between 39 and 120. The star copolymers were soluble in acidic water at pH 4 giving transparent or slightly opaque solutions, with the exception of the very hydrophobic DMAEMA(10)-b-MMA(30)-star, which gave a very opaque solution. Only the random copolymer star was completely dispersed in neutral water, giving a very opaque solution. The effective pKs of the copolymer stars were determined by hydrogen ion titration and were found to be in the range 6.5-7.6. The pHs of precipitation of the star copolymer solutions/dispersions were found to be between 8.8-10.1, except for the most hydrophobic DMA-EMA(10)-b-MMA(30)-Star, which gave a very opaque solution over the whole pH range. (c) 2006 Elsevier Ltd. All rights reserved.

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An experimental research addressing the effects of concrete composition and strength on anchorage bond behavior of prestressing reinforcement is presented to clarify the effect of material properties that have appeared contradictory in previous literature. Bond stresses and anchorage lengths have been obtained in twelve concrete mixes made up of different cement contents (C) – 350 to 500 kg/m3 – and water/cement (w/c) ratios – 0.3 to 0.5 – with compressive strength at 24 h ranging from 24 to 55 MPa. A testing technique based on measuring the prestressing force in specimens with different embedment lengths has been used. The results show that anchorage length increases when w/c increases, more significantly when C is higher; the effect of C reveals different trends based on w/c. The obtained anchorage bond stresses are greater for higher concrete compressive strength, and their average ratio of 1.45 with respect to transmission bond stresses implies a potential bond capacity.

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Parasites play pivotal roles in structuring communities, often via indirect interactions with non-host species. These effects can be density-mediated (through mortality) or trait-mediated (behavioural, physiological and developmental), and may be crucial to population interactions, including biological invasions. For instance, parasitism can alter intraguild predation (IGP) between native and invasive crustaceans, reversing invasion outcomes. Here, we use mathematical models to examine how parasite-induced trait changes influence the population dynamics of hosts that interact via IGP. We show that trait-mediated indirect interactions impart keystone effects, promoting or inhibiting host coexistence. Parasites can thus have strong ecological impacts, even if they have negligible virulence, underscoring the need to consider trait-mediated effects when predicting effects of parasites on community structure in general and biological invasions in particular.

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Background: Epidemiologic evidence on the influence of dietary glycemic index (GI) and glycemic load (GL) on the development of obesity is limited.

Objective: This prospective study examined the associations between dietary GI and GL and changes in body composition measures during adolescence.

Design: In a representative sample of Northern Irish adolescents aged 12 years at baseline and 15 years at follow-up (n=426), dietary intake was assessed by a diet history interview. Body composition measures included body mass index (BMI; kg m(-2)), BMI z-score, sum of four skinfold thicknesses, percentage body fat, fat mass index (FMI; kg m(-2)) and fat-free mass index (kg m(-2)).

Results: After adjustment for potential confounding factors, baseline GI was associated with increased change in FMI. Mean (95% confidence interval) values of changes in FMI according to tertiles of baseline GI were 0.41 (0.25, 0.57), 0.42 (0.26, 0.58) and 0.67 (0.51, 0.83) kg m(-2), respectively (P for trend=0.03). There was no significant association of baseline GI with changes in other body composition measures (P for trend0.054). Conversely, baseline GL showed no association with changes in any of the measures (P for trend0.41). Furthermore, changes in GI or GL were not associated with changes in any of the measures (P for trend0.16).

Conclusion: Dietary GI at age 12 years was independently associated with increased change in FMI between ages 12 and 15 years in a representative sample from Northern Ireland, whereas dietary GL showed no association with changes in any of the body composition measures examined.

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The granular product being designed in this work required the use of two different powders namely limestone and teawaste; these materials have different bulk and particle densities. The overall aim of the project was to obtain a granular product in the size range of 2 to 4. mm. The two powders were granulated in different proportions using carboxymethylcellulose (CMC) as the binder. The effect of amount of binder added, relative composition of the powder, and type of teawaste on the product yield was studied. The results show that the optimum product yield was a function of both relative powder composition and the amount of binder used; increasing the composition of teawaste in the powder increased the amount of binder required for successful granulation. An increase in the mass fraction of teawaste in the powder mix must be accompanied by an increase in the amount of binder to maintain the desired product yield.

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This chapter discusses the potential uses of both found poetry and imitiation poetry as teaching material for undergraduate creative poetry students.

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AIMS: The effect of dietary sucrose on insulin resistance and the pathogenesis of diabetes and vascular disease is unclear. We assessed the effect of 5% versus 15% sucrose intakes as part of a weight maintaining, eucaloric diet in overweight/obese subjects.

METHODS: Thirteen subjects took part in a randomised controlled crossover study (M:F 9:4, median age 46 years, range 37-56 years, BMI 31.7±0.9 kg/m(2)). Subjects completed two 6 week dietary periods separated by 4 week washout. Diets were designed to have identical macronutrient profile. Insulin action was assessed using a two-step hyperinsulinaemic euglycaemic clamp; glucose tolerance, vascular compliance, body composition and lipid profiles were also assessed.

RESULTS: There was no change in weight or body composition between diets. There was no difference in peripheral glucose utilization or suppression of endogenous glucose production. Fasting glucose was significantly lower after the 5% diet. There was no demonstrated effect on lipid profiles, blood pressure or vascular compliance.

CONCLUSION: A low-sucrose diet had no beneficial effect on insulin resistance as measured by the euglycaemic glucose clamp. However, reductions in fasting glucose, one hour insulin and insulin area under the curve with the low sucrose diet on glucose tolerance testing may indicate a beneficial effect and further work is required to determine if this is the case. Clinical Trial Registration number ISRCTN50808730.